BIOS 255 Week 4: Hematology and Cardiovascular Anatomy 2026
Chamberlain College
1. What is the primary function of erythrocytes?
A. Phagocytosis of pathogens
B. Transport of oxygen and carbon dioxide
C. Initiation of the clotting process
D. Production of antibodies
Answer: B
Rationale: Erythrocytes (red blood cells) contain hemoglobin, which binds to and
transports oxygen to tissues and carbon dioxide to the lungs.
2. Which plasma protein is most important for maintaining osmotic pressure?
A. Fibrinogen
B. Globulin
C. Hemoglobin
D. Albumin
Answer: D
Rationale: Albumin is the most abundant plasma protein and is key to maintaining blood
osmotic pressure, preventing fluid loss to tissues.
,3. Hematocrit is a measure of the percentage of what in a blood sample?
A. Red blood cells
B. Plasma proteins
C. Platelets
D. White blood cells
Answer: A
Rationale: Hematocrit measures the volume percentage of red blood cells in whole blood.
4. Which hormone, produced by the kidneys, stimulates red blood cell
production?
A. Renin
B. Thrombopoietin
C. Erythropoietin
D. Aldosterone
Answer: C
Rationale: Erythropoietin (EPO) is released by the kidneys in response to low oxygen
levels to stimulate the bone marrow to produce RBCs.
5. Which white blood cell is typically the most numerous in a healthy adult?
A. Neutrophils
B. Monocytes
C. Lymphocytes
D. Basophils
Answer: A
Rationale: Neutrophils are the most common leukocytes, making up 50-70% of the white
blood cell count.
, 6. What is the average lifespan of a red blood cell?
A. 10 days
B. 30 days
C. 1 year
D. 120 days
Answer: D
Rationale: RBCs lack a nucleus and organelles, limiting their lifespan to approximately 120
days before being recycled in the spleen or liver.
7. Which type of leukocyte releases histamine and heparin during an
inflammatory response?
A. Basophils
B. Eosinophils
C. Neutrophils
D. Lymphocytes
Answer: A
Rationale: Basophils contain granules filled with histamine (vasodilator) and heparin
(anticoagulant) for the inflammatory response.
8. Platelets are fragments of which large cell type?
A. Hemocytoblast
B. Reticulocyte
C. Megakaryocyte
D. Monoblast
Answer: C
Rationale: Platelets (thrombocytes) are formed from the fragmentation of large cells in the
bone marrow called megakaryocytes.
Chamberlain College
1. What is the primary function of erythrocytes?
A. Phagocytosis of pathogens
B. Transport of oxygen and carbon dioxide
C. Initiation of the clotting process
D. Production of antibodies
Answer: B
Rationale: Erythrocytes (red blood cells) contain hemoglobin, which binds to and
transports oxygen to tissues and carbon dioxide to the lungs.
2. Which plasma protein is most important for maintaining osmotic pressure?
A. Fibrinogen
B. Globulin
C. Hemoglobin
D. Albumin
Answer: D
Rationale: Albumin is the most abundant plasma protein and is key to maintaining blood
osmotic pressure, preventing fluid loss to tissues.
,3. Hematocrit is a measure of the percentage of what in a blood sample?
A. Red blood cells
B. Plasma proteins
C. Platelets
D. White blood cells
Answer: A
Rationale: Hematocrit measures the volume percentage of red blood cells in whole blood.
4. Which hormone, produced by the kidneys, stimulates red blood cell
production?
A. Renin
B. Thrombopoietin
C. Erythropoietin
D. Aldosterone
Answer: C
Rationale: Erythropoietin (EPO) is released by the kidneys in response to low oxygen
levels to stimulate the bone marrow to produce RBCs.
5. Which white blood cell is typically the most numerous in a healthy adult?
A. Neutrophils
B. Monocytes
C. Lymphocytes
D. Basophils
Answer: A
Rationale: Neutrophils are the most common leukocytes, making up 50-70% of the white
blood cell count.
, 6. What is the average lifespan of a red blood cell?
A. 10 days
B. 30 days
C. 1 year
D. 120 days
Answer: D
Rationale: RBCs lack a nucleus and organelles, limiting their lifespan to approximately 120
days before being recycled in the spleen or liver.
7. Which type of leukocyte releases histamine and heparin during an
inflammatory response?
A. Basophils
B. Eosinophils
C. Neutrophils
D. Lymphocytes
Answer: A
Rationale: Basophils contain granules filled with histamine (vasodilator) and heparin
(anticoagulant) for the inflammatory response.
8. Platelets are fragments of which large cell type?
A. Hemocytoblast
B. Reticulocyte
C. Megakaryocyte
D. Monoblast
Answer: C
Rationale: Platelets (thrombocytes) are formed from the fragmentation of large cells in the
bone marrow called megakaryocytes.
